[NTLK] MP2x00 Internal Interconnect Breakout
mm at matthiasm.com
Mon Jan 5 08:00:30 EST 2015
> On Jan 5, 2015, at 10:11 AM, Matthias Melcher <mm at matthiasm.com> wrote:
>> On Jan 5, 2015, at 2:37 AM, Jake Bordens <jake at allaboutjake.com> wrote:
>> He has code to toggle the DIO pin for Serial 3. What's interesting to me
>> is that the ROM actually has two functions already:
>> 0x0026d050 SerialPort0LineDriverConfig__16TVoyagerPlatformFUcT1
>> 0x0026d094 SerialPort3LineDriverConfig__16TVoyagerPlatformFUcT1
> Seems like I have to dive into the ROM ;-)
Sorry for the following total mess of information. Let me know if I should elaborate on any of this.
OK, some more technical information from "back then":
Serial Port 0 uses gpSerPortSel on pin 8. When gpSerPortSel switches high, the card must respond with a low on DCD (5).
TVoyagerPlatform::SerialPort0LineDriverConfig(unsigned char, unsigned char) writes to GPIO6 which is gpSerPortSel.
TVoyagerPlatform::PowerOnSubsystem(unsigned long) calls this function, but the value for gpSerPortSel is already inside the TVoyagerPlatform class.
The same is true for TVoyagerPlatform::PowerOffSubsystem(unsigned long)
but I can't find the code that would test any of the serial ports pins.
Aaah, here's a snippet I found in my docs:
Internal Modem connector
Port 0 (serial)
Pin Name Dir LTC1323
2 TDX I 4 TXD TXD+-
3 DTR I 5 TXI TXO
4 RTS I 6 /TXDEN
5 DCD O 9 /RXO /RXI
6 CTS O 10 RXO RXI
7 RXD O 11 RXD0 RXD+-
8 gpSerSel I 7 SHDN H -> shutdown chip
PortSel goes low, stays low if
TXD=H, DTR=L, RTS=H, DCD=H>L, CTS=L, RXD=H
Last annotation: SER 001 uses a LTC1323 and a hand full of caps (EMI Filters), but no other active parts.
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